Life in the universe
Microwave spectra for CH, OH, CO, NO,CN and NH (?) in space:
qualitative- and temperature- analysis
project 2013
( http://www.hi.is/~agust/Lif/Lifxx0213.doc )

The following microwave spectra will be analysed:
No.
Compound Temp. /
/AB
T(K)
A1
CO
298
A2
CO
600
A3
CO
20
A4
CO
298
B
CO
?
C
CO
?
D
298
?
E
?
?
F
?
?
G
298
?
H
?
?
I
?
?
J
298
?
K
?
?
L
?
?
M
?
?
N
?
?
O
?
?
P
?
?
Determine AB, T and LW

Linewidth/
LW
1
1
1
2
1
1
2
2
2
2
2
2
1
?
?
1
?
?
?
Spectrum in
computer:
a1y vs a1x
a2y vs a2x
a3y vs a3x
a4y vs a4x
by vs bx
cy vs cx
dy vs dx
ey vs ex
fy vs fx
gy vs gx
hy vs hx
iy vs ix
jy vs jx
ky vs kx
ly vs lx
my vs mx
ny vs nx
oy vs ox
py vs px
Spectroscopic constants:
Compound / molecule
B 1)
D 1)
CH (Methylidyne)
14.46
0.00145
OH (Hydroxyl radical)
18.91
19.4E-4
CO (carbon monoxide)
1.931
0.00000636
NO (nitric oxide)
1.672
0.54E-6
CN(cyano radical)
1.8997
6.4E-6
NH(Imidogen)
16.6993
17.097E-4
1) http://webbook.nist.gov/chemistry/form-ser.html.en-us.en
Signatures: _________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________

Performed on a computer (PC?) (See example HERE)
1. Open software (IGOR):
o Open explorer (e.g. Explorer, Firefox)
o type http://www.hi.is/~agust/Lif/
o Open (double click) Igor.exe (main software)
 RUN  RUN  OK (program starts)
o File  Open experiment
 Type (File name:) http://www.hi.is/~agust/Lif/rofa.pxp (e)
(http://www.hi.is/~agust/Lif/rof.pxp (ísl)) and press OPEN (spectrum
A1 appears)
o (Spectra can be enlarged and searched in detail: ask teacher)
2. Spectrum A1 (AB = CO/ T= 298K, LW = 1; a1y vs a1x) explored and simulated, e.g.:
 Macros -> Spectra calculations -> Newmolecule (new window appears)
 Type relevant spectroscopic constants according to table above (B = 1.931, D =
0.00000636)  Continue (calculations have been perforemd: w_gly vs w_glx)
 Compare the calculated and experimental spectra: Graph  Append Traces to
Graph  ..choose w_gly under Y Wave and w_glx under X Wave  Do it
(calculated spectrum appears in red; spectra differ due to different linewidths
(LW)).
 Change linewidth from 2 to 1, e.g.: choose “Newmolecule(1.931,298.15,"sticks
and bands","Yes",2,6.36e-06,23)” in bottom window (NB: B = 1.931, T = 298.15
LW = 2, D = 6.36e-06)  return (line moves to bottom)  change 2 to 1:
“ Newmolecule (1.931,298.15," sticks and bands ","Yes",1,6.36e-06,23)”  return
(Spectra will now match).
3. Explore and simulate A2 (AB = CO/ T= 600K, LW = 1; a2y vs a2x), e.g.:
 Windows  New Graph  ..choose a2y under Y Wave and a2x under X Wave 
Do it (measured spectrum appears in red)
 Change color of experimental spectrum (from red to black): position cursor (cross)
some place on the graph  double click  choose Color (black)  Do it
(spectrum becomes black)
Now similar analysis as in 2 can be performed:




Macros Spectra calculations  Newmolecule (new window appears)
Use appropriate number values  Continue (calculations have been performed:
w_gly vs w_glx)
Compare the calculated and experimental spectra: Graph  Append Traces to
Graph  ..choose w_gly under Y Wave and w_glx under X Wave  Do it
(calculated spectrum appears in red)
Parameters can now be changed analogous to that performed in 2 (near the end).
4. Perform simulations for the spectra listed above:
-Determine AB, T and LW.
- Replace „?“ in the table above with determined value.
- send the results to agust@hi.is